iLASIK® & Other Surgery Procedures

Eye mechanism

Before you receive LASIK or ICL surgery, it is important to understand how your eyes are functioning. There are conditions of normal vision, myopia, hypermetropia and astigmatism of the eyes, and by understanding the mechanism of how to see things, it is possible to understand each condition. To first accurately understand the condition of your own eyes is very important in order to properly determine the final decision on surgery.

Function

The cornea is the front part of the eye. Tears rinse dust off of the cornea when blinking. Next is the crystal lens, which has the function of adjusting its thickness to focus on things. Next is the corpus vitreum, which occupies the majority of the eye. The retina is at the very back. Light enters the cornea, and through the crystal lens it focuses on the retina. We can then see things when the image is read by the retina and transmitted to cerebrum.

eye

Normal vision

Light that enters the eye is refracted at the cornea and crystal lens, and focuses on the retina. In the condition of normal vision, the focus is on the retina when seeing at a distance.

eye

Myopia(Nearsightedness)

Light focuses in front of the retina because the axial length (length of the eyeball) is long or refractive power of cornea or crystal lens is too strong; therefore you can focus on things close by but not things far away.

Myopia(Nearsightedness)

Near view is easier to see but far view is blurry.

Hyperopia(Farsightedness)

Light takes the focus behind the retina because the axial length (length of the eyeball) is short or the refractive power of the cornea or crystal lens is too weak.



Hyperopia(Farsightedness)

Both near and far views are blurry.

Astigmatism

There is a slight corneal distortion. The image is blurry or you can see double or triple, because the curvature radius in vertical and horizontal directions is different such as in a rugby ball.


Astigmatism

Both near and far views are blurry.

Corneal structure

The cornea is a clear tissue without blood vessels, consisting of five layers. Thickness is approximately 0.5mm in the central part. This thin 0.5mm corneal tissue determines your visual acuity. You will have a better understanding of LASIK by knowing the structure of the tissue.

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